TrapiLib/lib/helpers/tree.js

const { Node, Link, Graph } = require("./graph");
class TreeNode extends Node {
	constructor(id){
		super(id);
		this.depth = null; 
	}
}

class Tree extends Graph {
	constructor(rootNode){
		super();
		this.root = rootNode;
		this.root.depth = 0;
		this.levels = [new Set([this.root.id])];
		super.addNode(this.root);
	}

  	addLink(link) {
  		console.log("You cannot add Link because its deprecated ...Use Insert");
		return;
	}
	addNode(node){
		console.log("You cannot add Node because its deprecated ...Use Insert");
		return;
	}

	changeParent(node, parent) {
		let link = this.links[node.id].in.values().next().value;
		let oldparent = link.from;
		this.links[oldparent.id].out.delete(link);
		link.from = parent;
		this.links[parent.id].out.add(link);
		this.updateLevels(parent);
	}

	updateLevels(node) {
		let outSet = this.links[node.id].out;
		for(let link of outSet) {
			let child = link.to;
			if(child.depth !== node.depth + 1) {
				this.levels[child.depth].delete(child.id);
				child.depth = node.depth + 1;
				this.levels[child.depth].add(child.id);
				this.updateLevels(child);
			}
		}
	}

	insert(node,parentNode){
		if(this.nodes[node.id]){
			throw new Error("Node already Exists")
		}
		if(!this.nodes[parentNode.id]){
			throw new Error("Parent Node does not Exist....Insert First ")
		}
		let link = new Link(parentNode,node);
		super.addNode(node);
		super.addLink(link);
		this.updateLevels(parentNode);
	}

	print() {
		console.log("§§§§§§§  Tree Structure 	 §§§§§§§§§§");

		this.levels.forEach((level, index) => {
			console.log("Level ", index);
			level.forEach( id => console.log(` ${id} `));
		});
		console.log("§§§§§§§  Tree Structure End §§§§§§§§§§");
	}

	remove(node){
		this.cleanup(node)
		this.levels[node.depth].delete(node.id);
		if(this.levels[node.depth].size === 0)
			this.levels.length = node.depth;

		super.removeNode(node);
	}

	cleanup(parent){
		let children = this.getChildren(parent);
		// console.log(children);
		children.forEach(child => {
			// console.log(child);
			this.remove(child)
		});

	}

	getChildren(node){
		// console.log(node)
		return [...this.links[node.id].out].map(link => link.to);
	}

	getLevel(depth) {
		return this.levels[depth];
	}

}

// var A = new TreeNode("A");
// let tree = new Tree(TreeNode,A);



// var B = new TreeNode('B');
// var C = new TreeNode('C');
// var D = new TreeNode('D');
// var E = new TreeNode('E');
// var F = new TreeNode("F");


// tree.insert(B,A)
// tree.insert(C,A)
// tree.insert(D,B)
// tree.insert(E,D)
// tree.insert(F,D)

// tree.print();

// tree.remove(D)

// tree.print();

module.exports = { Tree, TreeNode };